This invention relates to a sliding door for vehicles, especially automobiles, which is longitudinally and slidably guided, by means of a horizontally oriented guide bar extending along the length of the door, in a guide head, pivotally journalled about a vertical axis on a supporting arm itself pivotally mounted about a parallel axis on the vehicle body, whereby the sliding door, with alternate locking of the sliding movement and of the pivot bearing of its supporting device, is initially displaceable into an intermediate position parallel to its closed position and subsequently displaceable longitudinally of the vehicle.
For the correct functioning of such a sliding door for automobiles, it is essential that the door body, in its swung-in, closed position flush with the side wall of the vehicle body, and during the outward swinging of the door into its intermediate position parallel to this closed position, and also especially during the swinging-in from its intermediate position into its closed position, shall be locked to the guide head of the supporting device to prevent any longitudinal sliding, whereas on the other hand, during the sliding of the door longitudinally of the vehicle, the supporting device, especially the guide head, must be secured against an unintentional pivoting movement. For this purpose, provision was made in an earlier proposal, that the supporting device and especially its guide head, in its swung-out position, be automatically locked in the dead-centre position, secured by means of a tension spring attached to the vehicle body, of the supporting arm carrying the guide head and of a rod associated with the control of the pivoting movement of the guide head. This arrangement has however proved to be complicated and cumbersome and in particular does not permit a uniformly easy-running movement of the door body into its closed position, since the overcoming of the dead-centre position of the supporting device necessitates a considerable expenditure of force which, if the closure movement of the sliding door is slow, cannot be completely overcome by the inertia of the forward moving door.